With continuous developments of terminals, more and more intelligent devices support call functions. In addition, in order to prevent accidental touch during calls, the intelligent devices will mostly display black screens and cannot respond to the touch from users. At this time, if the users want to adjust sound volumes of the calls, it is usually necessary to manually press volume up keys and volume down keys. In this way, the lives of the volume keys will be shorten over time. Meanwhile, in some terminals, the volume keys are arranged in some positions such that the volume keys are capable of being pressed only after the terminals are moved away from ears, which is inconvenient for the users to use, and which brings great inconvenience during the calls. In addition, for existing terminals, only the sound volumes of earpieces can be adjusted during the calls, and the sound volumes of microphones cannot be adjusted. Therefore, when the sound volumes of the earpieces are adjusted to the maximum, the users can only raise or lower their sounds to make others heard, which brings great inconvenience to the users.
Therefore, it needs to make improvements and increase to the related art.